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1. PDRs4All: A JWST Early Release Science Program on Radiative Feedback from Massive Stars

Author: Olivier Berné, Émilie Habart, Els Peeters, Alain Abergel, Edwin A. Bergin, Jeronimo Bernard-Salas, Emeric Bron, Jan Cami, Emmanuel Dartois, Asunción Fuente, Javier R. Goicoechea, Karl D. Gordon, Yoko Okada, Takashi Onaka, Massimo Robberto, Markus Röllig, Alexander G. G. M. Tielens, Sílvia Vicente, Mark G. Wolfire, Felipe Alarcón, C. Boersma, Amélie Canin, Ryan Chown, Daniel Dicken, David Languignon, Romane Le Gal, Marc W. Pound, Boris Trahin, Thomas Simmer, Ameek Sidhu, Dries Van De Putte, Sara Cuadrado, Claire Guilloteau, Alexandros Maragkoudakis, Bethany R. Schefter, Thiébaut Schirmer, Stéphanie Cazaux, Isabel Aleman, Louis Allamandola, Rebecca Auchettl, Giuseppe Antonio Baratta, Salma Bejaoui, Partha P. Bera, Goranka Bilalbegović, John H. Black, Francois Boulanger, Jordy Bouwman, Bernhard Brandl, Philippe Brechignac, Sandra Brünken, Andrew Burkhardt, Alessandra Candian, Jose Cernicharo, Marin Chabot, Shubhadip Chakraborty, Jason Champion, Sean W. J. Colgan, Ilsa R. Cooke, Audrey Coutens, Nick L. J. Cox, Karine Demyk, Jennifer Donovan Meyer, Cécile Engrand, Sacha Foschino, Pedro García-Lario, Lisseth Gavilan, Maryvonne Gerin, Marie Godard, Carl A. Gottlieb, Pierre Guillard, Antoine Gusdorf, Patrick Hartigan, Jinhua He, Eric Herbst, Liv Hornekaer, Cornelia Jäger, Eduardo Janot-Pacheco, Christine Joblin, Michael Kaufman, Francisca Kemper, Sarah Kendrew, Maria S. Kirsanova, Pamela Klaassen, Collin Knight, Sun Kwok, Álvaro Labiano, Thomas S.-Y. Lai, Timothy J. Lee, Bertrand Lefloch, Franck Le Petit, Aigen Li, Hendrik Linz, Cameron J. Mackie, Suzanne C. Madden, Joëlle Mascetti, Brett A. McGuire, Pablo Merino, Elisabetta R. Micelotta, Karl Misselt, Jon A. Morse, Giacomo Mulas, Naslim Neelamkodan, Ryou Ohsawa, Alain Omont, Roberta Paladini, Maria Elisabetta Palumbo, Amit Pathak, Yvonne J. Pendleton, Annemieke Petrignani, Thomas Pino, Elena Puga, Naseem Rangwala, Mathias Rapacioli, Alessandra Ricca, Julia Roman-Duval, Joseph Roser, Evelyne Roueff, Gaël Rouillé, Farid Salama, Dinalva A. Sales, Karin Sandstrom, Peter Sarre, Ella Sciamma-O’Brien, Kris Sellgren, Matthew J. Shannon, Sachindev S. Shenoy, David Teyssier, Richard D. Thomas, Aditya Togi, Laurent Verstraete, Adolf N. Witt, Alwyn Wootten, Nathalie Ysard, Henning Zettergren, Yong Zhang, Ziwei E. Zhang, Junfeng Zhen, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), University of Western Ontario (UWO), Carl Sagan Center, SETI Institute, University of Michigan [Ann Arbor], University of Michigan System, Analytic and Computational Research, Inc. - Earth Sciences (ACRI-ST), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Observatorio Astronomico Nacional, Madrid, Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universiteit Gent = Ghent University (UGENT), Space Telescope Science Institute (STSci), Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, Meisei University, The University of Tokyo (UTokyo), Leiden Observatory [Leiden], Universiteit Leiden, Johns Hopkins University (JHU), Instituto de Astrofísica e Ciências do Espaço (IASTRO), University of Maryland [College Park], University of Maryland System, NASA Ames Research Center (ARC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Signal et Communications (IRIT-SC), Institut de recherche en informatique de Toulouse (IRIT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Toulouse Mind & Brain Institut (TMBI), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut National Polytechnique (Toulouse) (Toulouse INP), Onsala Space Observatory (OSO), Chalmers University of Technology [Göteborg], Delft University of Technology (TU Delft), Universidade Federal de Itajubá, Bay Area Environmental Research Institute (BAER), Australian Synchrotron [Clayton], INAF - Osservatorio Astrofisico di Catania (OACT), Istituto Nazionale di Astrofisica (INAF), University of Zagreb, Laboratoire de physique de l'ENS - ENS Paris (LPENS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), University of Colorado [Boulder], Institute for Molecules and Materials [Nijmegen], Radboud University [Nijmegen], Wellesley College, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), University of British Columbia (UBC), National Radio Astronomy Observatory [Charlottesville] (NRAO), National Radio Astronomy Observatory (NRAO), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Rice University [Houston], Yunnan Observatories, Chinese Academy of Sciences [Changchun Branch] (CAS), Universidad de Chile = University of Chile [Santiago] (UCHILE), University of Virginia, Aarhus University [Aarhus], Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo] (IAG), Universidade de São Paulo = University of São Paulo (USP), San Jose State University [San Jose] (SJSU), European Southern Observatory (ESO), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Academia Sinica, Institute of Astronomy of the Russian Academy of Sciences (INASAN), Russian Academy of Sciences [Moscow] (RAS), UK Astronomy Technology Centre (UK ATC), Science and Technology Facilities Council (STFC), Telespazio, Services par satellites, Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), University of Missouri [Columbia] (Mizzou), University of Missouri System, Max Planck Institute for Astronomy (MPIA), CAS Key Laboratory of Crust–Mantle Materials and Environments [Hefei], School of Earth and Space Sciences [Hefei], University of Science and Technology of China [Hefei] (USTC)-University of Science and Technology of China [Hefei] (USTC)-Chinese Academy of Sciences [Beijing] (CAS), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), University of California [Berkeley] (UC Berkeley), University of California (UC), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Massachusetts Institute of Technology (MIT), Instituto de Ciencia de Materiales de Madrid (ICMM), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Steward Observatory, University of Arizona, INAF - Osservatorio Astronomico di Cagliari (OAC), United Arab Emirates University (UAEU), National Astronomical Observatory of Japan (NAOJ), Banaras Hindu University [Varanasi] (BHU), University of Amsterdam [Amsterdam] (UvA), Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Universidade Federal do Rio Grande do Sul [Porto Alegre] (UFRGS), University of California [San Diego] (UC San Diego), University of Nottingham, UK (UON), Ohio State University [Columbus] (OSU), Space Science Institute [Boulder] (SSI), Stockholm University, Texas State University, Ritter Astrophysical Research Center, University of Toledo, National Sun Yat-Sen University (NSYSU), Star and Planet Formation Laboratory, ITA, USA, GBR, FRA, DEU, ESP, AUS, BEL, BRA, CHL, TWN, HRV, DNK, JPN, IND, NLD, PRT, CHN, RUS, SWE, National Aeronautics and Space Administration (US), University of Maryland, University of Michigan, Centre National de la Recherche Scientifique (France), Centre National D'Etudes Spatiales (France), Natural Sciences and Engineering Research Council of Canada, Ministerio de Ciencia e Innovación (España), German Research Foundation, Japan Society for the Promotion of Science, San José State University Research Foundation, Berné, Olivier, Habart, Émilie, Peeters, Els, Abergel, Alain, Bergin, Edwin A., Bernard-Salas, Jeronimo, Bron, Emeric, Cami, Jan, Dartois, Emmanuel, Fuente, Asunción, Goicoechea, Javier R., Gordon, Karl D., Okada, Yoko, Onaka, Takashi, Robberto, Massimo, Röllig, Markus, Tielens, Alexander G.G.M., Vicente, Sílvia, Wolfire, Mark G., Alarcón, Felipe, Boersma, C., Canin, Amélie, Chown, Ryan, Dicken, Daniel, Le Gal, Romane, Pound, Marc W., Trahin, Boris, Sidhu, Ameek, Van De Putte, Dries, Cuadrado, Sara, Guilloteau, Claire, Maragkoudakis, Alexandros, Schefter, Bethany R., Schirmer, Thiébaut, Aleman, Isabel, Allamandola, Louis, Auchettl, Rebecca, Antonio Baratta, Giuseppe, Bejaoui, Salma, Bera, Partha P., Bilalbegović, Goranka, Black, John H., Boulanger, Francois, Bouwman, Jordy, Brandl, Bernhard, Brünken, Sandra, Burkhardt, Andrew, Candian, Alessandra, Cernicharo, José, Chakraborty, Shubhadip, Champion, Jason, Colgan, Sean W.J., Cooke, Ilsa R., Coutens, Audrey, Cox, Nick L.J., Demyk, Karine, Donovan Meyer, Jennifer, Engrand, Cécile, Foschino, Sacha, Gavilan, Lisseth, Gerin, Maryvonne, Godard, Marie, Gottlieb, Carl A., Guillard, Pierre, Gusdorf, Antoine, Hartigan, Patrick, He, Jinhua, Herbst, Eric, Hornekaer, Liv, Janot-Pacheco, Eduardo, Joblin, Christine, Kaufman, Michael, Kemper, Francisca, Kendrew, Sarah, Kirsanova, Maria S., Klaassen, Pamela, Knight, Collin, Kwok, Sun, Labiano, Álvaro, Lai, Thomas S.Y., Lee, Timothy J., Lefloch, Bertrand, Le Petit, Franck, Li, Aigen, Linz, Hendrik, MacKie, Cameron J., Madden, Suzanne C., Mascetti, Joëlle, McGuire, Brett A., Merino, Pablo, Micelotta, Elisabetta R., Morse, Jon A., Molecular Spectroscopy (HIMS, FNWI), and HIMS (FNWI)
Subjects: Gaseous Nebulae, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, FELIX Infrared and Terahertz Spectroscopy, Star Forming Regions, Astrophysics - Astrophysics of Galaxies, Infrared Telescopes, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, [INFO]Computer Science [cs], Photodissociation Regions, Astrophysics::Earth and Planetary Astrophysics, Polycyclic Aromatic Hydrocarbons, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], James Webb Space Telescope (JWST), Photo-Dissociation Regions (PDRs), Massive stars, Orion Bar, MIRI, NIRSpec, NIRCam, Astrophysics::Galaxy Astrophysics
Abstract: 22 pags., 8 figs., 1 tab., Massive stars disrupt their natal molecular cloud material through radiative and mechanical feedback processes. These processes have profound effects on the evolution of interstellar matter in our Galaxy and throughout the universe, from the era of vigorous star formation at redshifts of 1-3 to the present day. The dominant feedback processes can be probed by observations of the Photo-Dissociation Regions (PDRs) where the far-ultraviolet photons of massive stars create warm regions of gas and dust in the neutral atomic and molecular gas. PDR emission provides a unique tool to study in detail the physical and chemical processes that are relevant for most of the mass in inter-and circumstellar media including diffuse clouds, proto-planetary disks, and molecular cloud surfaces, globules, planetary nebulae, and star-forming regions. PDR emission dominates the infrared (IR) spectra of star-forming galaxies. Most of the Galactic and extragalactic observations obtained with the James Webb Space Telescope (JWST) will therefore arise in PDR emission. In this paper we present an Early Release Science program using the MIRI, NIRSpec, and NIRCam instruments dedicated to the observations of an emblematic and nearby PDR: the Orion Bar. These early JWST observations will provide template data sets designed to identify key PDR characteristics in JWST observations. These data will serve to benchmark PDR models and extend them into the JWST era. We also present the Science-Enabling products that we will provide to the community. These template data sets and Science-Enabling products will guide the preparation of future proposals on star-forming regions in our Galaxy and beyond and will facilitate data analysis and interpretation of forthcoming JWST observations., Support for JWST-ERS program ID 1288 was provided through grants from the STScI under NASA contract NAS5-03127 to STScI (K.G., D.V.D.P., M.R.), Univ. of Maryland (M.W., M.P.), Univ. of Michigan (E.B., F.A.), and Univ. of Toledo (T.S.-Y.L.). O.B. and E.H. are supported by the Programme National “Physique et Chimie du Milieu Interstellaire” (PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES, and through APR grants 6315 and 6410 provided by CNES. E. P. and J.C. acknowledge support from the National Science and Engineering Council of Canada (NSERC) Discovery Grant program (RGPIN-2020-06434 and RGPIN-2021-04197 respectively). E.P. acknowledges support from a Western Strategic Support Accelerator Grant (ROLA ID 0000050636). J.R.G. and S.C. thank the Spanish MCINN for funding support under grant PID2019-106110GB-I00. Work by M.R. and Y.O. is carried out within the Collaborative Research Centre 956, subproject C1, funded by the Deutsche Forschungsgemeinschaft (DFG)—project ID 184018867. T.O. acknowledges support from JSPS Bilateral Program, grant No. 120219939. M.P. and M.W. acknowledge support from NASA Astrophysics Data Analysis Program award #80NSSC19K0573. C.B. is grateful for an appointment at NASA Ames Research Center through the San José State University Research Foundation (NNX17AJ88A) and acknowledges support from the Internal Scientist Funding Model (ISFM) Directed Work Package at NASA Ames titled: “Laboratory Astrophysics—The NASA Ames PAH IR Spectroscopic Database.”
Published: 2022
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2. Water Clusters in Interaction with Corannulene in a Rare Gas Matrix: Structures, Stability and IR Spectra

Author: Heloïse Leboucher, Joëlle Mascetti, Christian Aupetit, Jennifer A. Noble, Aude Simon, Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and ANR-13-BS08-0005,PARCS,Réactivité des PAH en matrices cryogéniques et sur la glace(2013)
Subjects: matrix isolation FTIR spectroscopy, corannulene, PAHs, astrochemistry, [SDU]Sciences of the Universe [physics], water clusters, DFTB, BOMD, [CHIM.CHEM]Chemical Sciences/Cheminformatics
Abstract: The interaction of polycyclic aromatic hydrocarbons (PAHs) with water is of paramount importance in atmospheric and astrophysical contexts. We report here a combined theoretical and experimental study of corannulene-water interactions in low temperature matrices and of the matrix’s influence on the photoreactivity of corannulene with water. The theoretical study was performed using a mixed density functional based tight binding/force field approach to describe the corannulene-water clusters trapped in an argon matrix, together with Born-Oppenheimer molecular dynamics to determine finite-temperature IR spectra. The results are discussed in the light of experimental matrix isolation FTIR spectroscopic data. We show that in the solid phase, π isomers of (C20H10)(H2O)n, with n = 2 or 3, are energetically favored. These π complexes are characterized by small shifts in corannulene vibrational modes and large shifts in water bands. These π structures, particularly stable in the case of the water trimer where the water cluster is trapped “inside” the corannulene bowl, may account for the difference in photoreactivity of non-planar–compared to planar–PAHs with water. Indeed, planar PAHs such as pyrene and coronene embedded in H2O:Ar matrices form σ isomers and react with water to form alcohols and quinones under low energy UV irradiation, whereas no photoreactivity was observed for corannulene under the same experimental conditions.
Published: 2022
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3. Clathrate hydrates FTIR spectroscopy to understand cometary ices

Author: Natalia Esteves Lopez, Aurélie Guilbert-Lepoutre, Stéphane Coussan, Joëlle Mascetti, Arnaud Desmedt, and Christian Aupetit
Abstract: Comet nuclei in the transneptunian region are submitted to heating at temperatures from 30 to 50 K over the age of the solar system [1]. The timescale for sublimated volatiles to escape the objects at these temperatures is long though [1]. Once these nuclei enter the inner solar system and become active, subsurface sublimation puts a gas phase in contact of the porous and tortuous ice structure of cometary material. In this context, the formation of clathrate hydrates may be considered as a plausible trapping mechanism of these gases, occurring in subsurface layers, and allowing some of the most volatile species to subsequently survive in cometary material at temperatures higher than the sublimation temperature of the corresponding pure solid [2]. Hydrates are ice-like crystalline compounds, resulting from the tridimensional stacking of cages of H-bonded water molecules. Clathrates are gas hydrates, meaning that the guests are gas molecules encased in a host framework of water molecules. Gas hydrates only form and remain stable in specific temperature and pressure regimes that depend on the nature of the guest molecules [3]. Theoretical phase diagram of clathrate hydrates show that it would be possible to form clathrates at very low pressure (10-10 bar) and temperature (< 80 K), but there is a critical lack of experimental data using these preparation methods [4]. Could clathrate hydrates be formed under conditions relevant to the interior of comet nuclei? The formation and characterization of these ice-like structures under such conditions could provide valuable experimental evidence for understanding the preservation of some volatile species during the thermally-induced evolution of comets. In an effort to assess whether hydrates may play a role in maintaining volatile species in cometary material, FTIR spectroscopic identification of several species have been performed. We present results related to carbon dioxide and methane hydrates, in conditions relevant to cometary nuclei, i.e. at low temperature (10 K) and pressure (base pressure 10-7 mbar) regimes. To understand the nature of the gas hydrates formed under these conditions, vibrational spectra of distinct gas/ice interactions (clathrate hydrate, gas in/on water ice) were compared. The behaviour of the water crystalline skeleton interactions with the trapped molecules at different temperatures, as well as the influence of the gas mixture and the deposition method, will be presented. Acknowledgements This study is part of a project that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 802699). [1] Prialnik et al. (2004) in Comets II, Festou, Keller and Weaver (Eds.), 359-387 [2] Mandt et al. (2017) in Comets as Tracers of Solar System Formation and Evolution, Mandt, Mousis, Bockel{\'e}e-Morvan and Russel (Eds.) [3] Sloan (2003) Nature, 426, 353-359 [4] Choukroun et al. (2003) in The Science of Solar System Ices, Gudipati and Castillo-Roguez (Eds.), 409-454
Published: 2021
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4. Infrared matrix-isolation and theoretical studies of interactions between CH3I and water

Author: Joëlle Mascetti, Hanaa Houjeij, Anne Cecile Gregoire, Laurent Cantrel, Stéphane Coussan, Sonia Taamalli, Sophie Sobanska, Christian Aupetit, Florent Louis, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 (PC2A), Université de Lille-Centre National de la Recherche Scientifique (CNRS), PSN-RES/SEREX/L2EC, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), UMR 5255 - INSTITUT DES SCIENCES MOLÉCULAIRES, UMR 8522 - PC2A - PHYSICOCHIMIE DES PROCESSUS DE COMBUSTION ET DE L'ATMOSPHÈRE, Université de Lille, CNRS, PhysicoChimie des Processus de Combustion et de l'Atmosphère (PC2A), Centre national de la recherche scientifique, Université Lille 1 (CNRS, UL1), Centre National de la Recherche Scientifique (CNRS), UMR 5255 - Institut des Sciences moléculaires, Centre national de la recherche scientifique (CNRS), Laboratoire d'Expérimentation Environnement et Chimie (IRSN/PSN-RES/SEREX/L2EC), Service d'Etude et de Recherche EXpérimentale (IRSN/PSN-RES/SEREX), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), and Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Chemistry, Organic Chemistry, Matrix isolation, Solvation, Halide, Context (language use), 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Analytical Chemistry, Inorganic Chemistry, Atmosphere, 13. Climate action, Halogen, Cloud condensation nuclei, [CHIM]Chemical Sciences, Dispersion (chemistry), Spectroscopy, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Gaseous iodomethane are naturally emitted in the atmosphere over oceans through the algae and phytoplankton activities. The fate of naturally emitted iodomethane is of great interest because of the oxidizing properties of iodine in the atmosphere and its impact on the catalytic destruction of the ozone layer. Additionally, iodomethane is one of the gaseous species that can be emitted in the case of severe nuclear accident. The radiological impact of gaseous iodomethane is of concerns and requires knowledge about its behavior in the atmosphere. Water is one of the major species in the atmosphere which is responsible for atmospheric aerosol nucleation and thus, for cloud condensation nuclei (CCN). The fundamental knowledge concerning the interaction between methyl iodine and water at the molecular scale contributes to the better understanding of the fate of such species into the atmosphere and their role in CCN formation. Here the microhydration of iodomethane was investigated using cryogenic matrix experiments which were supported by theoretical DFT calculations. A large excess of water regarding CH3I was used in order to mimic atmospheric conditions. Dimers and trimers of CH3I are observed despite the high water amount in the initial mixture together with hetero aggregates between CH3I and water clusters. This may be explained by the low affinity of CH3I with water. Considering the concentration of iodomethane used in our experiments, the aggregates are rather formed in gas phase and not in the matrix cage. The interaction between CH3I and H2O molecules studied experimentally and supported by DFT calculation highlights that, in the atmosphere, gaseous iodomethane and water will likely form association between water and iodomethane aggregates instead of (CH3I)n-(H2O)m hetero complexes. Our results have important consequences for the understanding of the alkyl halide solvation in primary processes and contribute to the understanding of reactive halogen species in tropospheric chemistry. In the context of a nuclear severe accident, our work is contributing to better understand the fate of nuclear species in the atmosphere and thus, the radionuclide dispersion.
Published: 2021
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5. Perturbation of the Surface of Amorphous Solid Water by the Adsorption of Polycyclic Aromatic Hydrocarbons

Author: Joëlle Mascetti, Céline Toubin, Eric Michoulier, Christian Aupetit, Jennifer A. Noble, Aude Simon, Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ANR-13-BS08-0005,PARCS,Réactivité des PAH en matrices cryogéniques et sur la glace(2013), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC)
Subjects: Chemical substance, Materials science, Analytical chemistry, FOS: Physical sciences, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Adsorption, Physics - Chemical Physics, Physical and Theoretical Chemistry, Solar and Stellar Astrophysics (astro-ph.SR), Chemical Physics (physics.chem-ph), 021001 nanoscience & nanotechnology, Perturbation (geology), Astrophysics - Astrophysics of Galaxies, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Amorphous solid, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, General Energy, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Astrophysics of Galaxies (astro-ph.GA), Amorphous ice, 0210 nano-technology, Science, technology and society
Abstract: This joint theoretical and experimental study establishes that the adsorption of polycyclic aromatic hydrocarbons (PAHs) onto the amorphous ice surface provokes a broadening and redshift of the "dangling" OH (dOH) ice spectral feature, the redshift increasing with PAH size up to $\sim$ 85~cm$^{-1}$. It also reveals that, in certain interaction configurations, adsorption induces substantial reorganisation of the hydrogen-bonding network at the ice surface. Comparison with experiments validates the novel theoretical methodology relying on the density functional based tight binding approach, which offers a compromise between system size and accuracy enabling a wide sampling of surface structures. Applied in an astrophysical context, this study suggests that widening of the dOH feature by adsorption of aromatic molecules could explain its absence heretofore in observational ice spectra, offering hope that future missions with higher sensitivity will verify its presence or absence in dense regions., Comment: Published in J. Phys. Chem. C
Published: 2020
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6. Insights into the Photodecomposition of Azidomethyl Methyl Sulfide: A S 2 /S 1 Conical Intersection on Nitrene Potential Energy Surfaces Leading to the Formation of S -Methyl- N -sulfenylmethanimine

Author: Luís Pinto da Silva, Manuel Algarra, Adel Reisi-Vanani, M. Soledad Pino-González, Fabien Borget, Juan Soto, J. Enrique Rodríguez-Borges, Rafael Luque, Joëlle Mascetti, Universidade da Madeira (UMA), Universidad de Málaga [Málaga] = University of Málaga [Málaga], Universidade do Porto, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), University of Kashan, Universidad de Córdoba [Cordoba], Universidade do Porto = University of Porto, Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Universidad de Córdoba = University of Córdoba [Córdoba]
Subjects: 010304 chemical physics, Chemistry, Reaction step, Nitrene, MS-CASPT2, Photodissociation, Matrix isolation, Infrared spectroscopy, Intersystem crossing, Conical intersection, 010402 general chemistry, Photochemistry, CASSCF, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Conical Intersection, 0103 physical sciences, UV Photochemistry, Singlet state, Physical and Theoretical Chemistry, Spectroscopy, [CHIM.OTHE]Chemical Sciences/Other, Matrix Isolation
Abstract: International audience; UV photodecomposition of azidomethyl methyl sulfide (AMMS) yields a transient S-methylthiaziridine which rapidly evolves to S-methyl-N-sulfenylmethanimine at 10 K. This species was detected by infrared matrix isolation spectroscopy. The mechanism of the photoreaction of AMMS has been investigated by a combined approach, using low-temperature matrix isolation FTIR spectroscopy in conjunction with two theoretical methods, namely, complete active space self-consistent field and multiconfigurational second-order perturbation. The key step of the reaction is governed by a S2/S1 conical intersection localized in the neighborhood of the singlet nitrene minimum which is formed in the first reaction step of the photolysis, that is, N2 elimination from AMMS. Full assignment of the observed infrared spectra of AMMS has been carried out based on comparison with density functional theory and second-order perturbation Møller–Plesset methods.
Published: 2020
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7. Ultrafast electronic relaxations from the S 3 state of pyrene

Author: Dominique Descamps, Jennifer A. Noble, Stéphane Petit, Christian Aupetit, Aude Simon, Joëlle Mascetti, Valérie Blanchet, Nadia Ben Amor, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre d'Etudes Lasers Intenses et Applications (CELIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Groupe Méthodes et outils de la chimie quantique (LCPQ) (GMO), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Bordeaux (UB), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), and ANR-13-BS08-0005,PARCS,Réactivité des PAH en matrices cryogéniques et sur la glace(2013)
Subjects: Materials science, Wave packet, Relaxation (NMR), Ab initio, General Physics and Astronomy, 02 engineering and technology, PAH, 010402 general chemistry, 021001 nanoscience & nanotechnology, Internal conversion (chemistry), femtochimie, 01 natural sciences, 0104 chemical sciences, Ab initio quantum chemistry methods, Excited state, Complete active space, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Atomic physics, 0210 nano-technology, Excitation
Abstract: International audience; The ultrafast relaxation occurring in pyrene upon excitation at 4.68 eV was studied in a supersonic gas-jet fs pump-probe experiment. Mass spectrometry and velocity map imaging of photoelectrons produced by probing via multiphoton ionisation at 800 nm reveal that the initially prepared wave packet exhibits a fast relaxation (¡80 fs), followed by a slower one of 200 fs. By comparing the propensity rules of photoionisation observed at one color with ab initio calculations, we tentatively assign these two timescales to a first internal conversion to the dark bB 3g state followed by a second one to the long lived aB 2u first excited state. Vertical excitation energies determined using ab initio Multi-State Complete Active Space 2nd order Perturbation Theory (MS-CASPT2), as well as oscillator strengths between several electronic states, are reported.
Published: 2019
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8. Ultrafast electronic relaxations from the S

Author: Jennifer A, Noble, Christian, Aupetit, Dominique, Descamps, Stéphane, Petit, Aude, Simon, Joëlle, Mascetti, Nadia, Ben Amor, and Valérie, Blanchet
Abstract: The ultrafast relaxation occurring in pyrene upon excitation at 4.68 eV was studied in a supersonic gas-jet fs pump-probe experiment. Mass spectrometry and velocity map imaging of photoelectrons produced by probing via multiphoton ionisation at 800 nm reveal that the initially prepared wave packet exhibits a fast relaxation (80 fs), followed by a slower one of 200 fs. By comparing the propensity rules of photoionisation observed at one color with ab initio calculations, we tentatively assign these two timescales to a first internal conversion to the dark bB3g state followed by a second one to the long lived aB2u first excited state. Vertical excitation energies determined using ab initio Multi-State Complete Active Space 2nd order Perturbation Theory (MS-CASPT2), as well as oscillator strengths between several electronic states, are reported.
Published: 2019

9. Correction: Adsorption of PAHs on interstellar ice viewed by classical molecular dynamics

Author: Céline Toubin, Aude Simon, Jennifer A. Noble, Eric Michoulier, and Joëlle Mascetti
Subjects: Physics, Molecular dynamics, Adsorption, Interstellar ice, General Physics and Astronomy, Thermodynamics, Physical and Theoretical Chemistry
Abstract: Correction for ‘Adsorption of PAHs on interstellar ice viewed by classical molecular dynamics’ by Eric Michoulier et al., Phys. Chem. Chem. Phys., 2018, DOI: 10.1039/c8cp00593a.
Published: 2018

10. Adsorption of PAHs on interstellar ice viewed by classical molecular dynamics

Author: Aude Simon, Jennifer A. Noble, Céline Toubin, Joëlle Mascetti, Eric Michoulier, Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupement de Recherche (GDR) 533 EMIE Edifices Moléculaires Isolés et Environnés, GENCI 2016-A0010806820, ANR-13-BS08-0005,PARCS,Réactivité des PAH en matrices cryogéniques et sur la glace(2013), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Surface diffusion, Materials science, 010304 chemical physics, Molecular cloud, Interstellar ice, Binding energy, General Physics and Astronomy, Context (language use), Ovalene, 01 natural sciences, Interstellar medium, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Adsorption, chemistry, 13. Climate action, Chemical physics, 0103 physical sciences, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physics::Chemical Physics, Physical and Theoretical Chemistry, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) are a family of molecules which represent the best candidates to explain the observation of one set of features in the Interstellar Medium (ISM): the Aromatic Interstellar Bands (AIBs). They could also contribute to the Diffuse Interstellar Bands (DIBs). In dense molecular clouds, PAHs may condense onto interstellar grains, contributing to the complex chemistry occurring in their icy mantles, composed essentially of water. In this context, the adsorption of various aromatic molecules, from benzene to ovalene, on different ices – both amorphous and crystalline – is investigated by means of classical molecular dynamics simulations. Initially, a systematic parametrization of the electronic charges on the chosen PAHs in these environments is carried out, and benchmarked with reference to free energies of solvation in liquid water. Then we propose a new, rigorous methodology, transferable to any other PAH or molecular species, to evaluate the charges to be applied to the molecule in the gas phase, at interfaces, or in liquid water. Ultimately, the adsorption energies calculated for the various PAHs are used to derive a function predicting the adsorption energy of any PAH on a given ice surface as a function of the number of C and H atoms it contains. For all PAHs studied, the largest adsorption energies are found on the crystalline hexagonal ice surface (Ih). Binding energy maps constructed for each PAH–ice pair give valuable insight into adsorption site densities and the barriers to surface diffusion. One key result is that the amorphous surface offers a smaller number of adsorption sites compared to that of hexagonal ice. A direct correlation between the location of energetically favourable adsorption sites and the presence of dangling H-bonds is also demonstrated using these maps, showing that PAHs adsorb preferentially on sites offering dangling H-bonds. The present work represents a complete description of PAH–ice interaction in the ground electronic state and at low temperature, providing the binding energies and barrier heights necessary to the ongoing improvement of astrochemical models.
Published: 2018
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11. Photochemistry of Fe:H2O Adducts in Argon Matrixes: A Combined Experimental and Theoretical Study in the Mid-IR and UV–Visible Regions

Author: Jennifer A. Noble, Aude Simon, Sandra Latournerie, Nadia Ben Amor, Vincent Deguin, Christian Aupetit, Joëlle Mascetti, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Groupe Méthodes et outils de la chimie quantique (LCPQ) (GMO), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Argon, Astrochemistry, 010304 chemical physics, chemistry.chemical_element, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Catalysis, Adduct, Interstellar medium, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Monomer, chemistry, 13. Climate action, 0103 physical sciences, Molecule, Irradiation, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; The photochemistry of Fe:H2O adducts is of interest in fields as diverse as catalysis and astrochemistry. Industrially, iron can be used as a catalyst to convert H2O to H2, whereas in the interstellar medium it may be an important component of dust grains, influencing the chemistry on their icy surfaces. This study consisted of the deposition and spectral characterization of binary systems of atomic iron with H2O in cryogenic argon matrixes. In this way, we were able to obtain information about the interaction of the two species; we observed the formation of adducts of iron monomers and dimers with water molecules in the mid-IR and UV–visible spectral domains. Upon irradiation with a UV radiation source, the iron species were inserted into the water molecules to form HFeOH and HFe2OH, leading in some cases to the formation of FeO possibly accompanied by the production of H2. DFT and correlated multireference wave function calculations confirmed our attributions. This combination of IR and UV–visible spectroscopy with theoretical calculations allowed us to determine, for the first time, the spectral characteristics of iron adducts and their photoproducts in the UV–visible and in the OH stretching region of the mid-IR domain.
Published: 2018
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12. Electronic spectroscopy of protonated 1-aminopyrene in a cold ion trap

Author: Claude Dedonder-Lardeux, Jennifer A. Noble, Christophe Jouvet, Joëlle Mascetti, Institut des Sciences Moléculaires (ISM), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ANR-13-BS08-0005,PARCS,Réactivité des PAH en matrices cryogéniques et sur la glace(2013), and Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Organic Chemistry, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], Analytical chemistry, Protonation, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, Biochemistry, Tautomer, Electron spectroscopy, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Fragmentation (mass spectrometry), Ab initio quantum chemistry methods, Excited state, Physics::Atomic and Molecular Clusters, Pyrene, Ion trap, Physics::Chemical Physics, Nuclear Experiment, 0210 nano-technology
Abstract: In aromatic systems that contain an amino group, there is competition between protonation on a carbon atom of the skeleton and protonation on the amino group. Herein, we studied the photofragmentation of protonated 1-aminopyrene in a cold ion trap and mainly observed the protonated amino tautomer, which led to fragmentation pathways through the loss of H or NH3 groups. Several excited states were assigned, among which the fourth excited state showed broadened bands, thus indicating a fast decay that was attributed to the presence of a πσ* charge-transfer state by comparison of the experimental results with ab initio calculations. We deduced the πσ* transition energies in protonated aromatic amino compounds of increasing size directly from the ionization potentials of the neutral aromatic unsubstituted molecules. Tautomers that were protonated on a carbon atom of the pyrene skeleton were also weakly observed, and we showed that two tautomers that were protonated on a carbon atom of the aromatic ring could be distinguished by using electronic spectroscopy.
Published: 2017
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13. Formation of coronene:water complexes: FTIR study in argon matrices and theoretical characterisation

Author: Audrey Moudens, Guillaume Rouaut, Aude Simon, Jennifer A. Noble, Christophe Iftner, Christian Aupetit, Joëlle Mascetti, Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), LERMA Cergy (LERMA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Argon, Absorption of water, Matrix isolation, General Physics and Astronomy, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Coronene, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Tight binding, chemistry, Ionization, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Organic chemistry, Physical chemistry, Molecule, Physical and Theoretical Chemistry, Fourier transform infrared spectroscopy, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract: In this paper, we report a combined theoretical and experimental study of coronene:water interactions in low temperature argon matrices. The theoretical calculations were performed using the mixed density functional-based tight binding/force field approach. The results are discussed in the light of experimental matrix isolation FTIR spectroscopic data. We show that, in the solid phase, (C24H12)(H2O)n (n ≤ 6) σ-type complexes, i.e. with water molecules coordinated on the edge of coronene, are formed, whereas in the gas phase, π-interaction is preferred. These σ-complexes are characterised by small shifts in water absorption bands and a larger blue shift of the out-of-plane γ(CH) deformation of coronene, with the shift increasing with the number of complexed water molecules. Such σ interaction is expected to favour photochemical reaction between water and coronene at the edges of the coronene molecule, leading to the formation of oxidation products at low temperature, even in the presence of only a few water molecules and at radiation energies below the ionisation potential of coronene.
Published: 2017
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14. Photochemistry of Pyrene with Water at Low Temperature: Study of Atmospherical and Astrochemical Interest

Author: Christian Aupetit, Zohra Guennoun, and Joëlle Mascetti
Subjects: Extraterrestrial Environment, Surface Properties, Ultraviolet Rays, chemistry.chemical_element, Infrared spectroscopy, Photochemistry, Vibration, Polyaromatic hydrocarbon, chemistry.chemical_compound, Adsorption, Molecule, Argon, Physical and Theoretical Chemistry, Pyrenes, Atmosphere, Chemistry, Spectrum Analysis, Ice, Temperature, Water, Photochemical Processes, Tautomer, Amorphous solid, Pyrene
Abstract: Photochemistry of a polyaromatic hydrocarbon, pyrene C(16)H(10), with water has been investigated at cryogenic temperatures. Photoprocessing of this species, performed at λ > 235 nm, in argon matrices, adsorbed onto amorphous water surfaces, and trapped in solid water, led to the formation of ketonic isomers, C(16)H(10)O, and possibly quinones. These species have been identified for the first time by infrared spectroscopy with the support of isotopic substitution experiments and DFT calculations. These oxidized pyrene-like species, of atmospherical and astrochemical interest, most likely arise from a tautomeric rearrangement of their analogous hydroxylated molecules, these latter being formed by reaction of water with pyrene cations.
Published: 2011
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15. Water clusters in an argon matrix: infrared spectra from molecular dynamics simulations with a self-consistent charge density functional-based tight binding/force-field potential

Author: Aude Simon, Fernand Spiegelman, Joëlle Mascetti, Christophe Iftner, Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut des Sciences Moléculaires (ISM), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010304 chemical physics, molecular dynamic simulation, Chemistry, Charge density, Infrared spectroscopy, 010402 general chemistry, Energy minimization, 01 natural sciences, Force field (chemistry), 0104 chemical sciences, Molecular dynamics, Tight binding, 0103 physical sciences, Potential energy surface, Cluster (physics), [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Atomic physics, ComputingMilieux_MISCELLANEOUS
Abstract: The present theoretical study aims at investigating the effects of an argon matrix on the structures, energetics, dynamics, and infrared (IR) spectra of small water clusters (H2O)n (n = 1-6). The potential energy surface is obtained from a hybrid self-consistent charge density functional-based tight binding/force-field approach (SCC-DFTB/FF) in which the water clusters are treated at the SCC-DFTB level and the matrix is modeled at the FF level by a cluster consisting of ∼340 Ar atoms with a face centered cubic (fcc) structure, namely (H2O)n/Ar. With respect to a pure FF scheme, this allows a quantum description of the molecular system embedded in the matrix, along with all-atom geometry optimization and molecular dynamics (MD) simulations of the (H2O)n/Ar system. Finite-temperature IR spectra are derived from the MD simulations. The SCC-DFTB/FF scheme is first benchmarked on (H2O)Arn clusters against correlated wave function results and DFT calculations performed in the present work, and against FF data available in the literature. Regarding (H2O)n/Ar systems, the geometries of the water clusters are found to adapt to the fcc environment, possibly leading to intermolecular distortion and matrix perturbation. Several energetical quantities are estimated to characterize the water clusters in the matrix. In the particular case of the water hexamer, substitution and insertion energies for the prism, bag, and cage are found to be lower than that for the 6-member ring isomer. Finite-temperature MD simulations show that the water monomer has a quasifree rotation motion at 13 K, in agreement with experimental data. In the case of the water dimer, the only large-amplitude motion is a distortion-rotation intermolecular motion, whereas only vibration motions around the nuclei equilibrium positions are observed for clusters with larger sizes. Regarding the IR spectra, we find that the matrix environment leads to redshifts of the stretching modes and almost no shift of the bending modes. This is in agreement with experimental data. Furthermore, in the case of the water monomer and dimer, the magnitudes of the computed shifts are in fair agreement with the experimental values. The complex case of the water hexamer, which presents several low-energy isomers, is discussed.
Published: 2015
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16. The gas phase reaction between CO2 and lanthanide atoms. A test of a model for the isokinetic effect

Author: Ragnar Larsson and Joëlle Mascetti
Subjects: Lanthanide, chemistry.chemical_compound, Chemistry, Energy transfer, Inorganic chemistry, Carbon dioxide, Thermodynamics, Physical and Theoretical Chemistry, Catalysis, Gas phase
Abstract: Using literature data on the gas phase reaction between free lanthanide atoms and carbon dioxide, we have found an isokinetic relation for seven of the twelve investigated elements with an isokinetic temperature, Tiso, of 2500±330 K. This value is analyzed in the framework of the model of selective energy transfer, SET, indicating that metal-CO2 complexes are formed as pre-reaction states. The result is in accordance with the fundamental concepts of SET.
Published: 2005
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17. Theoretical Investigation of the Reactivity of Copper Atoms with Carbon Disulfide

Author: Joëlle Mascetti, Yana Dobrogorskaya, Yacine Hannachi, and Alexander Nemukhin, and Imre Pápai
Subjects: Carbon disulfide, Chemistry, Inorganic chemistry, chemistry.chemical_element, Endothermic process, Copper, Dissociation (chemistry), Gas phase, chemistry.chemical_compound, Coupled cluster, Potential energy surface, Mole, Physical chemistry, Physical and Theoretical Chemistry
Abstract: The mechanism of the Cu + CS2 reaction has been investigated using density functional and coupled cluster calculations. The lowest energy route on the potential energy surface corresponds to the insertion product SCuCS via the formation of intermediate coordination complexes: η1S and η2CS, which all lie below the energy of the reactants. Another path corresponding to the formation of a cyclic C2v compound η2SS leads to the same insertion product, but it involves a higher energy barrier (34.7 kcal/mol vs 26.9 kcal/mol with respect to the reactants at the CCSD(T) level). The dissociation of the insertion product SCuCS into the CuS and CS fragments is found to be endothermic by 43 kcal/mol (CCSD(T) level). Our results are related to experimental data obtained in low-temperature rare gas matrixes and in the gas phase.
Published: 2003
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18. Infrared spectroscopy studies and MNDO/d calculations in organosilylborane series

Author: J. Araujo da Silva, Daniel Liotard, Joëlle Mascetti, J.C. Rayez, Jean-Paul Pillot, Jean-Pierre Desvergne, Marie-Thérèse Rayez, and Marc Birot
Subjects: Inorganic Chemistry, Symmetry element, Chemistry, Absorption band, Organic Chemistry, Analytical chemistry, Infrared spectroscopy, Physical chemistry, Molecule, MNDO, Spectroscopy, Analytical Chemistry
Abstract: A series of organosilylboranes has been investigated by IR spectroscopy and semiempirical calculations (MNDO/d force field methods). Computational studies afforded Si–B stretching wavenumbers in good agreement with the experimental IR bands observed in the range of 480–650 cm −1 . It was shown that these characteristic Si–B bond vibrations depend on the structure of molecules and on the size of substituting groups. Thus, compounds possessing small and medium substituting groups (H, Me) and those having a symmetry element give pure Si–B stretching bands. In the case of silylboranes bearing bulky groups, assignments of bands involving Si–B vibrators were achieved via comparison of experimental and theoretical IR spectra with those of reference molecules containing the parent organosilyl- or organoboryl moieties. An experimental absorption band near 600 cm −1 could reasonably be assigned to ν (Si–B).
Published: 2003
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19. 2A‘ and 2A‘ ‘ Energy Surfaces for the Sc + CO2 → ScO + CO Reaction

Author: Joëlle Mascetti, Yacine Hannachi, Gábor Schubert, and Imre Pápai
Subjects: Reaction mechanism, Crystallography, Coupled cluster, Computational chemistry, Chemistry, Excited state, State (functional analysis), Physical and Theoretical Chemistry, Ground state, Potential energy, Energy (signal processing), Doublet state
Abstract: The mechanism of the title reaction has been investigated using density functional and coupled cluster calculations. The results indicate that the lowest energy path corresponds to the η2CO coordination of CO2 followed by the insertion of Sc into a C−O bond. We show that two doublet state (2A‘ and 2A‘ ‘) potential energy surfaces have to be considered to describe the reaction mechanism. On the 2A‘ surface, the reaction gives a weakly bound OScCO species that can easily dissociate into ground state ScO(2Σ+) + CO products, whereas the 2A‘ ‘ state insertion complex is thermodynamically stable because it correlates to an excited state of ScO. The applicability of the B3LYP and CCSD(T) methods for the relative stability of intermediates is examined, and our results are related to available experimental findings.
Published: 2002
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20. Vanadium Insertion into CO2, CS2 and OCS: A Comparative Theoretical Study

Author: Yacine Hannachi, Joëlle Mascetti, Imre Pápai, and Sylvain Gwizdala
Subjects: Vanadium, chemistry.chemical_element, Potential energy, Adduct, Metal, chemistry.chemical_compound, Crystallography, chemistry, Insertion reaction, Computational chemistry, visual_art, Atom, visual_art.visual_art_medium, Molecule, Density functional theory, Physical and Theoretical Chemistry
Abstract: The reactions of the ground-state V(s2d3) atom with CO2, CS2, and OCS molecules have been studied at the B3LYP level of density functional theory in order to compare the insertion process for these three isovalent molecules. The relative stabilities of the adduct and insertion forms are calculated. The reaction barrier between these two forms are estimated for each system from the 4A‘ ‘ and 4A‘ potential energy curves defined in terms of the C−X (X=O,S) intrinsic reaction coordinate. The barrier to metal insertion from the side-on structure is rather low (ca 4 kcal/mol) for CO2 and CS2, however, whereas V(CO2) is well above the OVCO insertion product, the V(CS2) complex is only 4.2 less stable than SVCS. Consequently, coordination of CS2 to metal centers is stronger than that of CO2. Our calculations indicate no energy barrier for the insertion of V in the CS bond of OCS, whereas the insertion in the CO bond is less favored than in CO2. We show that each insertion reaction proceeds on a single potential e...
Published: 2002
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21. Mechanism of formation of the peroxocarbonate complex (PCy3)2Ni(CO4) from solid (PCy3)2Ni(CO2) and dioxygen: an example of solid-state metallorganic reaction involving CO2 deco-ordination and reinsertion into the OO bond of (PCy3)2Ni(O2). Reactivity of the peroxocarbonate complex towards olefins in the solid state and in solution

Author: Michele Aresta, M. Fouassier, Angela Dibenedetto, Joëlle Mascetti, and Immacolata Tommasi
Subjects: Phosphine oxide, Olefin fiber, Reaction mechanism, Allene, Photochemistry, Resonance (chemistry), Inorganic Chemistry, chemistry.chemical_compound, chemistry, Transfer agent, Materials Chemistry, Reactivity (chemistry), Physical and Theoretical Chemistry, Phosphine
Abstract: Solid (PCy3)2Ni(CO2) (1) reacts with dioxygen to afford the peroxocarbonate complex (PCy3)2Ni(CO4) (3). The use of labelled 13CO2, C18O2, 18O2 coupled with a FTIR study of both the gas-phase in equilibrium with the solid and the solid resulting complex, allows to propose the reaction mechanism that implies CO2 deco-ordination, O2 co-ordination, and CO2 insertion into the OO bond of the newly formed, reactive (PCy3)2Ni(O2) complex 2. A normal mode analysis substantiates the band assignment and the proposed mechanism. Peroxocarbonate (3) exhibits a 13C resonance at 166.6 ppm and a single 31P signal at 43.1 ppm below 200 K. The reactivity of the peroxo-group as one-oxygen transfer agent prevents the spectroscopic characterisation of 3 in solution at room temperature. An out-of-sphere phosphine can be easily oxidised. A gaseous olefin, mono-ene (ethylene) or diene (allene), added to 3, makes easier the deco-ordination process of one phosphine ligand, that is then oxidised to phosphine oxide. The gaseous olefin itself is not oxidised until free phosphine is present in the medium. In solution, styrene is oxidised through a two- or one-oxygen transfer pathway, according to the reaction condition.
Published: 2002
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22. Metal Coordination of CO2

Author: Joëlle Mascetti
Subjects: chemistry.chemical_classification, chemistry.chemical_compound, Nucleophile, chemistry, Inorganic chemistry, Molecule, Reactivity (chemistry), Metal carbon dioxide complex, Photochemistry, Organometallic chemistry, Metal sulfur dioxide complex, Catalysis, Coordination complex
Abstract: Even though carbon dioxide is used in a great number of industrial applications, it remains a molecule with low reactivity. Its activation by coordination to metal complexes is used in both stoichiometric and catalytic reactions. This article describes the different kinds of metal carbon dioxide complexes observed in the gas phase, in cryogenic solids, and in solution, and briefly presents the reactivity of coordinated CO2 toward electrophiles and nucleophiles. Keywords: carbon dioxide; transition-metal complexes; activation of small molecules; coordination chemistry; organometallic chemistry
Published: 2014
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23. The photodimerisation of trans-cinnamic acid and its derivatives: a study by vibrational microspectroscopy

Author: Samantha D.M. Allen, Jean-Luc Bruneel, Andrew Gilbert, Matthew J. Almond, Joëlle Mascetti, and Peter Hollins
Subjects: Microscopy, Photochemistry, Dimer, Photodissociation, Spectrum Analysis, Raman, Vibration, Atomic and Molecular Physics, and Optics, Cinnamic acid, Analytical Chemistry, Crystal, symbols.namesake, chemistry.chemical_compound, Monomer, chemistry, Cinnamates, Spectroscopy, Fourier Transform Infrared, symbols, Electronic effect, Raman spectroscopy, Dimerization, Instrumentation, Single crystal, Spectroscopy
Abstract: Infrared and Raman spectroscopies have been used to monitor the [2+2] photodimerisation reactions of α-trans-cinnamic acid and of a number of its derivatives. The principal changes observed in the spectra upon dimerisation are decay of a band around 1637 cm−1, which is assigned to ν(CC) of the ethene bond of the monomer, and growth of bands just above 3000 cm−1, which result from ν(CH) of saturated carbon atoms of the dimer. The use of microscope attachments has allowed us to follow the reactions of single crystals and we conclude that the reactions are topotactic in nature. We have carried out preliminary kinetic experiments in which spectra of one single crystal are recorded after sequential periods of photolysis. We find that the rates of dimerisation of differently substituted cinnamic acids are similar, with physical effects, such as the thickness of an individual crystal, outweighing any observed electronic effects (inductive or mesomeric).
Published: 2000
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24. Carbon dioxide interaction with metal atoms: matrix isolation spectroscopic study and DFT calculations

Author: F. Galan, Imre Pápai, and Joëlle Mascetti
Subjects: Binding energy, Inorganic chemistry, Matrix isolation, chemistry.chemical_element, Inorganic Chemistry, Metal, Nickel, chemistry, visual_art, Atom, Materials Chemistry, visual_art.visual_art_medium, Physical chemistry, Molecule, Moiety, Density functional theory, Physical and Theoretical Chemistry
Abstract: This paper collects the results obtained in different studies on the interaction of the CO 2 molecule with transition metal atoms, using matrix isolation FTIR spectroscopy and density functional theory (DFT). Late-transition metal atoms (Fe, Co, Ni and Cu) form one-to-one M(CO 2 ) complexes, while those from the left-hand side in the periodic table (Ti, V, and Cr) insert spontaneously into a CO bond yielding oxocarbonyl species. Owing to isotopic experiments with 13 CO 2 and C 18 O 2 , these results allow spectroscopic identification of carbon dioxide bonding modes in organometallic species containing CO 2 moiety. Special attention is paid to the interaction of CO 2 molecule with Ni and Ti atoms. In neat CO 2 matrices, it is shown that CO 2 is side-on coordinated to nickel in a 1:1 complex. The binding energy is weak (18 kcal mol −1 ). In argon diluted matrices, no reaction occurs, even after annealing. Interestingly, the coordination of CO 2 is promoted by adding N 2 in the rare gas matrix. This is rationalized by comparing the potential energy curves corresponding to the interaction of the Ni atom or the NiN 2 moiety with CO 2 . The binding energy is then 32 kcal mol −1 . DFT calculations show that Ti inserts with no energy barrier into a CO bond, resulting in an OTiCO insertion product, which is far more stable than any of the possible Ti(CO 2 ) complexes and reactive towards CO 2 . An intrinsic reaction path for the insertion process is investigated.
Published: 1999
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25. CO2 Coordination to Nickel Atoms: Matrix Isolation and Density Functional Studies

Author: F. Galan, Imre Pápai, M. Fouassier, Joëlle Mascetti, and Michel Tranquille
Subjects: Argon, Inorganic chemistry, Binding energy, Matrix isolation, chemistry.chemical_element, Nickel, chemistry, Physical chemistry, Molecule, Density functional theory, Astrophysics::Earth and Planetary Astrophysics, Physics::Chemical Physics, Physical and Theoretical Chemistry, Fourier transform infrared spectroscopy, Spectroscopy, Physics::Atmospheric and Oceanic Physics
Abstract: The interaction of the CO2 molecule with nickel atoms was studied by using matrix isolation spectroscopy and density functional theory. In argon dilute matrices, no reaction occurs, even after annealing the deposit. In neat CO2 matrices, it is shown that carbon dioxide forms a 1:1 complex with nickel which is characterized by its UV−visible and FTIR absorptions, including isotopically labeled species. Theory predicts the side-on coordination mode to be the most stable. The binding energy of the side-on Ni(CO2) complex is estimated to be 18 kcal/mol. The calculated OCO angle is 145°, which is quite a large value compared to those encountered in other known CO2 complexes. In dinitrogen matrices, the yield of CO2 complexation is considerably enhanced relative to that in argon dilute and neat CO2 matrices, which is attributed to the formation of unsaturated Ni(N2)n complexes prior to CO2 coordination. The CO2 binding energies calculated for the Ni(CO2)(N2)n (n = 1, 2) complexes (respectively 32 and 4 kcal/mol...
Published: 1997
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26. On the chemical reactions of carbon dioxide isoelectronic molecules CS2 and OCS with 1-butyl-3-methylimidazolium acetate

Author: Noël Pinaud, João A. P. Coutinho, M. Isabel Cabaço, Marcel Besnard, Fabián Vaca Chávez, Joëlle Mascetti, Yann Danten, and Pedro J. Sebastião
Subjects: PHASE, Liquid phase, 010402 general chemistry, 01 natural sciences, Chemical reaction, Catalysis, Ion, chemistry.chemical_compound, symbols.namesake, SYSTEMS, SULFIDE, Materials Chemistry, Molecule, Organic chemistry, 010405 organic chemistry, Metals and Alloys, DITHIOCARBOXYLATES, General Chemistry, C4mim, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, IONIC LIQUIDS, Carbon dioxide, Ceramics and Composites, 1-butyl-3-methylimidazolium acetate, symbols, CO2, COMPLEXES, Raman spectroscopy
Abstract: Made available in DSpace on 2017-12-07T19:49:09Z (GMT). No. of bitstreams: 2 license.txt: 2154 bytes, checksum: 4b0f01eb19f34a0ae8b22225f6f5120c (MD5) On the chemical reactions of carbon dioxide isoelectronic molecules CS2 and OCS with 1-butyl-3-methylimidazolium acetate_10.1039c3cc46038j.pdf: 833580 bytes, checksum: 8ca5923cc4a015c4577c68b695e9cee3 (MD5) Previous issue date: 2013
Published: 2013

27. CO2 in 1-butyl-3-methylimidazolium acetate. 2. NMR investigation of chemical reactions

Author: Joëlle Mascetti, Yann Danten, M. Isabel Cabaço, Fabián Vaca Chávez, Pedro J. Sebastião, João A. P. Coutinho, Marcel Besnard, Noël Pinaud, Institut des Sciences Moléculaires (ISM), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), Centro de Fisica Atomica, Universidade de Lisboa (ULISBOA), Centro de Investigacao em Materiais Ceramicaos e Compositos (CICECO), and Universidade de Aveiro
Subjects: [PHYS]Physics [physics], Magnetic Resonance Spectroscopy, 010405 organic chemistry, Inorganic chemistry, Solvation, Imidazoles, Nuclear magnetic resonance spectroscopy, Carbon Dioxide, Reference Standards, 010402 general chemistry, Mole fraction, 01 natural sciences, Chemical reaction, 0104 chemical sciences, Acetic acid, chemistry.chemical_compound, chemistry, Carboxylation, [SDE]Environmental Sciences, [CHIM]Chemical Sciences, Molecule, Organic chemistry, Carboxylate, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS
Abstract: The solvation of CO(2) in 1-butyl-3-methylimidazolium acetate (Bmim Ac) has been investigated by (1)H, (13)C, and (15)N NMR spectroscopy at low CO(2) molar fraction (mf) (x(CO(2)) ca. 0.27) corresponding to the reactive regime described in part 1 of this study. It is shown that a carboxylation reaction occurs between CO(2) and Bmim Ac, leading to the formation of a non-negligible amount (~16%) of 1-butyl-3-methylimidazolium-2-carboxylate. It is also found that acetic acid molecules are produced during this reaction and tend to form with elapsed time stable cyclic dimers existing in pure acid. A further series of experiments has been dedicated to characterize the influence of water traces on the carboxylation reaction. It is found that water, even at high ratio (0.15 mf), does not hamper the formation of the carboxylate species but lead to the formation of byproduct involving CO(2). The evolution with temperature of the resonance lines associated with the products of the reactions confirms that they have a different origin. The main byproduct has been assigned to bicarbonate. All these results confirm the existence of a reactive regime in the CO(2)-Bmim Ac system but different from that reported in the literature on the formation of a reversible molecular complex possibly accompanied by a minor chemical reaction. Finally, the reactive scheme interpreting the carboxylation reaction and the formation of acetic acid proposed in the literature is discussed. We found that the triggering of the carboxylation reaction is necessarily connected with the introduction of carbon dioxide in the IL. We argue that a more refined scheme is still needed to understand in details the different steps of the chemical reaction in the dense phase.
Published: 2012
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28. Vibrational spectroscopy and molecular dynamics of water monomers and dimers adsorbed on polycyclic aromatic hydrocarbons

Author: Aude Simon, Joëlle Mascetti, Mathias Rapacioli, Fernand Spiegelman, Modélisation, Agrégats, Dynamique (LCPQ) (MAD), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC)
Subjects: Water dimer, 010304 chemical physics, Chemistry, Binding energy, General Physics and Astronomy, Infrared spectroscopy, 010402 general chemistry, 01 natural sciences, Coronene, 0104 chemical sciences, chemistry.chemical_compound, Molecular dynamics, Chemical physics, Computational chemistry, 0103 physical sciences, Potential energy surface, Density functional theory, Physical and Theoretical Chemistry, Spectroscopy
Abstract: International audience; This paper reports structures, energetics, dynamics and spectroscopy of H2O and (H2O)2 systems adsorbed on coronene (C24H12), a compact polycyclic aromatic hydrocarbon (PAH). On-the-fly Born-Oppenheimer molecular dynamics simulations are performed for temperatures T varying from 10 to 300 K, on a potential energy surface obtained within the self-consistent-charge density-functional based tight-binding (SCC-DFTB) approach. Anharmonic infrared (IR) spectra are extracted from these simulations. We first benchmark the SCC-DFTB semi-empirical hamiltonian vs. DFT (Density Functional Theory) calculations that include dispersion, on (C6H6)(H2O)1,2 small complexes. We find that charge corrections and inclusion of dispersion contributions in DFTB are necessary to obtain consistent structures, energetics and IR spectra. Using this Hamiltonian, the structures, energetics and IR features of the low-energy isomers of (C24H12)(H2O)1,2 are found to be similar to the DFT ones, with evidence for a stabilizing edge-coordination. The temperature dependence of the motions of H2O and (H2O)2 on the surface of C24H12 is analysed, revealing ultra-fast periodic motion. The water dimer starts diffusing at a higher temperature than the water monomer (150 K vs. 10 K respectively), which appears to be consistent with the binding energies. Qualitative and quantitative analyses of the effects of T on the IR spectra are performed. Anharmonic factors in particular are derived and it is shown that they can be used as signatures for the presence of PAH-water complexes. Finally, this paper lays the foundations for the studies of larger (PAH)m(H2O)n clusters, that can be treated with the efficient computational approach benchmarked in this paper.
Published: 2012
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29. Carbon dioxide coordination chemistry. 3. Vibrational, NMR, theoretical studies of (carbon dioxide)bis(tricyclohexylphosphine)nickel

Author: Florent Ingold, M. Fouassier, Alain Dedieu, Michele Aresta, Joëlle Mascetti, Immacolata Tommasi, Corine. Jegat, and Michel Tranquille
Subjects: chemistry.chemical_classification, Infrared, Stereochemistry, Tricyclohexylphosphine, chemistry.chemical_element, Nuclear magnetic resonance spectroscopy, Coordination complex, Inorganic Chemistry, chemistry.chemical_compound, symbols.namesake, Nickel, chemistry, symbols, Physical chemistry, Physical and Theoretical Chemistry, Fourier transform infrared spectroscopy, Raman spectroscopy, Inorganic compound
Abstract: Complete assignments of FTIR and Raman spectra are proposed for Ni(CO 2 )(PCy 3 ) 2 and its 13 CO 2 - and C 18 O 2 -labeled derivatives. Normal coordinate analysis gives a relevant force-field for side-on complexation at the solid state and shows that the complex can also exist with an «end-on» coordination mode. FTIR study in various solvents at different temperatures allows us to conclude that similar coordination modes are found in solution. Results are compared to that obtained by 13 C and 31 P NMR (including CPMAS studies) concerning the fluxionality of Ni-(CO 2 )(PCy 3 ) 2
Published: 1993
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30. Photochemistry of tris(dimethylpyrazolyl)-boratorhodium dicarbonyl and bis(dimethylpyrazolyl)-boratorhodium dicarbonyl complexes in low temperature media at 12–298 K: some insights into CH activation processes

Author: Antony J. Rest, Joëlle Mascetti, and Peter E. Bloyce
Subjects: Tris, Denticity, Ligand, Organic Chemistry, Photodissociation, Matrix isolation, Infrared spectroscopy, Photochemistry, Biochemistry, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Nujol, Materials Chemistry, Physical and Theoretical Chemistry
Abstract: IR and electronic spectroscopic evidence, including a study of 13 CO enrichment pathways, is presented to show that photolysis of tris (dimethylpyrazolyl)-boratorhodium dicarbonyl and bis(dimethylpyrazolyl)-boratorhodium dicarbonyl complexes in argon and methane matrices at ca. 12 K produces CO loss and ligand dechelation products. No evidence was found for photochemical CH bond activation in methane matrices but the facile tridentate α bidentate interconversion for tris(dimethylpyrazolyl)-boratorhodium dicarbonyl provides support for the proposal that such a process could be the key step in the highly efficient CH photoactivation reaction of this complex at 298 K. In dinitrogen matrices the new CO loss products reacted to form monodinitrogen complexes. In an attempt to investigate whether additional thermal energy is needed for the photoactivation processes, the tris(dimethylpyrazolyl)-boratorhodium dicarbonyl and bis(dimethylpyrazolyl)-boratorhodium dicarbonyl complexes were photolysed in perfluorokerosine and Nujol mulls which could be warmed from ca. 12 K to 298 K. No CH bond photoactivation was observed in Nujol mulls at 12 K or 77 K but at 298 K photoactivation of Nujol by tris(dimethylpyrazolyl)-boratorhodium dicarbonyl was observed, i.e. there appears to be a thermal contribution to the photochemical CH activation process for this particular complex. The results of the low temperature studies are related to photochemical reactions observed in solutions at 298 K.
Published: 1993
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31. Carbon Dioxide Coordination Chemistry and Reactivity of Coordinated CO2

Author: Joëlle Mascetti
Subjects: chemistry.chemical_classification, chemistry.chemical_compound, Transition metal atoms, Chemistry, Inorganic chemistry, Carbon dioxide, Polymer chemistry, Reactivity (chemistry), Oxidative coupling of methane, Coordination complex
Published: 2010
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32. Raman infrared, and UV-visible studies of matrix-isolated nickel(0) complexes with ethylene, propylene, and butadiene

Author: Colette Cosse-Mertens, Said Bouchareb, Joëlle Mascetti, Florence Galan, Therese Merle-Mejean, and Michel Tranquille
Subjects: Ethylene, Absorption spectroscopy, Infrared, Stereochemistry, General Engineering, Matrix isolation, chemistry.chemical_element, Ethylene propylene rubber, Propene, symbols.namesake, Nickel, chemistry.chemical_compound, chemistry, symbols, Physical chemistry, Physical and Theoretical Chemistry, Raman spectroscopy
Abstract: The cocondensation products of nickel atoms with pure ethylene or ethylene-argon futures trapped at 12 K were reinvestigated by IR and UV-visible spectroscopies. The first Raman spectra were obtained. Isotopic H/D experiments and comparison of IR and Raman spectra indicate unambiguously that three complexes are formed, Ni(C 2 H 4 ) 3 , Ni(C 2 H 4 ) 2 , and Ni(C 2 H 4 ), with a normal order of increasing perturbation of ethylene vibration modes from the 1:3 to the 1:1 stoichiometries
Published: 1992
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33. Photolysis of Group VI metal carbonyls, (η6-C6H6)Cr(CO)3, (η5-C5H5)Mn(CO)3, (η5-CH3C5H4)Mn(CO)3 and (η5-C5H5)Re(CO)3 in Nujol at 77 K

Author: Thomas E. Bitterwolf, Joëlle Mascetti, Antony J. Rest, and Kimberly A. Lott
Subjects: chemistry.chemical_classification, Stereochemistry, Organic Chemistry, Photodissociation, Matrix isolation, Metal carbonyl, Biochemistry, Medicinal chemistry, Inorganic Chemistry, Metal, chemistry.chemical_compound, chemistry, Nujol, visual_art, Materials Chemistry, visual_art.visual_art_medium, Physical and Theoretical Chemistry, Inorganic compound
Abstract: Photolysis of M(CO) 6 , where M = Cr,Mo, and W, in Nujol mulls at 77K resulted in the formation of “free” CO and C 4 v M(CO) 5 photoproducts. This reaction was found to be photochemically and thermally reversible. Similarly, the photolysis of the metal “half-sandwich” complexes (η 6 -C 6 H 6 )Cr(CO) 3 , (η 5 -C 5 H 5 )Mn(CO) 3 , (η 5 -CH 3 C 5 H 4 )Mn(CO) 3 and (η 5 -C 5 H 5 )Re(CO) 3 in Nujol at 77 K was found to form the corresponding dicarbonyl photoproducts and “free” CO. These reactions were found to be photochemically reversible. (η 6 -C 6 H 6 )Cr(CO) 3 and (η 5 -C 5 )Re(CO) 3 were also found to produce small amounts of dinuclear products directly upon photolysis, while (η 5 -C 5 H 5 )Mn(CO) 3 and (η 5 -CH 3 C 5 H 4 )Mn(CO) 3 formed similar species upon annealing.
Published: 1991
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34. Carbon dioxide coordination chemistry. 2. Synthesis and FTIR study of (carbon dioxide)bis(cyclopentadienyl)(trimethylphosphine)titanium

Author: M. Fouassier, Corine. Jegat, Michel Tranquille, and Joëlle Mascetti
Subjects: chemistry.chemical_classification, Stereochemistry, Trimethylphosphine, chemistry.chemical_element, Coordination complex, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Cyclopentadienyl complex, Polymer chemistry, Carbon dioxide, Physical and Theoretical Chemistry, Fourier transform infrared spectroscopy, Titanium
Published: 1991
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35. Carbon dioxide coordination chemistry. 1. Vibrational study of trans-bis(carbon dioxide)tetrakis (trimethylphosphine)molybdenum and (carbon dioxide) tetrakis(trimethylphosphine)iron

Author: Corine. Jegat, M. Fouassier, and Joëlle Mascetti
Subjects: Inorganic Chemistry, chemistry.chemical_classification, chemistry.chemical_compound, chemistry, Stereochemistry, Molybdenum, Inorganic chemistry, Trimethylphosphine, Carbon dioxide, chemistry.chemical_element, Physical and Theoretical Chemistry, Coordination complex
Published: 1991
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36. Theoretical investigation of the reactivity of copper atoms with OCS: comparison with CS2 and CO2

Author: Yacine Hannachi, Joëlle Mascetti, Imre Pápai, Yana Dobrogorskaya, Laboratoire de Physico-Chimie Moléculaire (LPCM), Université Sciences et Technologies - Bordeaux 1-Centre National de la Recherche Scientifique (CNRS), Chemistry Department, Moscow State University, and Chemical Research Center of Has
Subjects: Exothermic reaction, Reaction mechanism, 010304 chemical physics, Chemistry, Activation energy, 010402 general chemistry, Photochemistry, 01 natural sciences, Endothermic process, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, Electron transfer, Models, Chemical, 0103 physical sciences, Atom, Molecule, Reactivity (chemistry), Physical and Theoretical Chemistry, Copper
Abstract: The reaction mechanism of the Cu atom with OCS and CO2 has been studied by means of density functional method (B3LYP). The overall energetics has been refined at the CCSD(T) level. In the case of the Cu + OCS reaction, the CS insertion route is found much more favorable than the CO insertion one. This later reaction is direct and involves an activation energy of 83.3 kcal/mol and is endothermic by 50.0 kcal/mol at the CCSD(T) level. The insertion into the CS bond proceeds through the eta1s and eta2cs coordination species as intermediates and is found exothermic by about 20 kcal/mol. The highest transition structure along this route is only 11.5 kcal/mol higher in energy than the reactant's ground states. In the case of the Cu + CO2 reaction, the insertion route into the CO bond is also found direct but with a lower endothermicity (30.6 kcal/mol) and smaller activation energy (61.1 kcal/mol) than that into the CO bond of OCS. In all cases, the insertion mechanism proceeds simultaneously with electron transfer from the Cu atom to OCS (or CO2) molecule.
Published: 2006
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37. Formation of peroxocarbonates from L3Rh(O2)Cl and L2Ni(CO2) : a unique reaction mechanism with carbon dioxide insertion into the O-O bond

Author: Michele Aresta, Eugenio Quaranta, Marek Borowiak, Michel Tranquille, Immacolata Tommasi, and Joëlle Mascetti
Subjects: chemistry.chemical_compound, Reaction mechanism, Transition metal, Chemistry, Transition metal dioxygen complex, Polymer chemistry, Carbon dioxide, Photochemistry
Abstract: Publisher Summary Transition-metal peroxocarbonates of formula L n M(CO 4 )X m are known since a long time. If the peroxocarbonate complexes are prepared by reaction of dioxygen complexes of transition metals L n M(O 2 )X m (M =Pd, Pt, Rh, Ir) with carbon dioxide, [1a] in principle, two ways are possible, that imply the formal insertion of carbon dioxide into the O-O or M-O bond.
Published: 1998
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38. Mechanism of Formation of Peroxocarbonates RhOOC(O)O(Cl)(P)(3) and Their Reactivity as Oxygen Transfer Agents Mimicking Monooxygenases. The First Evidence of CO(2) Insertion into the O-O Bond of Rh(eta(2)-O(2)) Complexes

Author: Eugenio Quaranta, Carlo Fragale, Joëlle Mascetti, Florence Galan, Immacolata Tommasi, Michele Aresta, Monique. Fouassier, and Michel Tranquille
Subjects: Inorganic Chemistry, chemistry.chemical_compound, Oxygen transfer, chemistry, Stereochemistry, Ligand, chemistry.chemical_element, Reactivity (chemistry), Physical and Theoretical Chemistry, Monooxygenase, Bond cleavage, Phosphine, Rhodium
Abstract: Extended labeling experiments have shown that formation of rhodium peroxocarbonate from CO(2) and [RhCl(eta(2)-O(2))(P)(3)] (P is PEt(2)Ph or PEtPh(2)) proceeds through O-O bond cleavage and CO(2) insertion. O-transfer to ancillary phosphine ligand to give R(3)P=O selectively (85%) involves the Rh-linked O atom of the peroxo group of RhCl(CO(4))(P)(3).
Published: 1996

39. Photochemistry of Pyrene with Water at Low Temperature: Study of Atmospherical and Astrochemical Interest.

Author: Zohra Guennoun, Christian Aupetit, and Joëlle Mascetti
Published: 2011
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40. The crystal chemistry of the new rare-earth sodium borates Na3Ln(BO3)2(Ln = La, Nd)

Author: Claude Fouassier, Joëlle Mascetti, and M. Vlasse
Subjects: Crystal chemistry, Chemistry, Sodium, Inorganic chemistry, chemistry.chemical_element, Crystal structure, Condensed Matter Physics, Neodymium, Electronic, Optical and Magnetic Materials, Inorganic Chemistry, Crystallography, X-ray crystallography, Materials Chemistry, Ceramics and Composites, Physical and Theoretical Chemistry, Ternary operation, Boron, Monoclinic crystal system
Abstract: The ternary borate systems Na2OLn2O3B2O3 (Ln = La, Nd) have been investigated in view of obtaining high-neodymium-concentration materials with weak concentration quenching. A ternary phase of composition Na3Ln(BO3)2 (Ln = La, Nd) has been found. It crystallizes in the monoclinic space group P2 1 c . The structure has been determined for Na3Nd(BO3)2. A full-matrix least-squares refinement led to R = 0.040. The structure is formed by isolated Bo3 triangles held together by the neodymium and sodium ions. The rare-earth atoms have a complex eightfold coordination in a covalent BO3 matrix.
Published: 1981
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41. Concentration quenching of the Nd3+ emission in alkali rare earth borates

Author: Claude Fouassier, Paul Hagenmuller, and Joëlle Mascetti
Subjects: chemistry.chemical_classification, Gadolinium, Inorganic chemistry, chemistry.chemical_element, Condensed Matter Physics, Alkali metal, Neodymium, Electronic, Optical and Magnetic Materials, Inorganic Chemistry, chemistry, Crystal field theory, Materials Chemistry, Ceramics and Composites, Lanthanum, Physical chemistry, Physical and Theoretical Chemistry, Ternary operation, Luminescence, Inorganic compound
Abstract: Four new ternary compounds with compositions Li6Nd(BO3)3, Na3Nd(BO3)2, and Na18Nd(BO3)7 have been found in the M2ONd2O3B2O3 systems, where M is either Li or Na. Concentration quenching of the neodymium emission in homologous lanthanum or gadolinium borates has been investigated. While in the Li6Gd(BO3)3, Na3La2(BO3)3, and Na3La(BO3)2 host lattices the quenching rate shows a quadratic dependence on Nd3+ concentration, as expected since the coordination polyhedra are connected by common faces or edges, in Na18La(BO3)7 the luminescent lifetime is not influenced by neodymium concentration. Lifetimes and crystal field splitting of the J levels are compared to those of other oxide host lattices.
Published: 1983
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42. Low temperature studies (12–293 K) of unstable species using Nujol mulls: reversible carbon monoxide ejection and carbon–hydrogen bond activation

Author: Antony J. Rest and Joëlle Mascetti
Subjects: chemistry.chemical_classification, Stereochemistry, Infrared, Analytical chemistry, Matrix isolation, Carbon–hydrogen bond activation, Atmospheric temperature range, chemistry.chemical_compound, chemistry, Nujol, Molecular Medicine, Spectroscopy, Inorganic compound, Carbon monoxide
Abstract: Infrared spectroscopic experiments using [W(CO)6] and [(η5-C5Me5)Ir(CO)2], which have previously been studied in gas matrices by matrix isolation spectroscopy, are presented which demonstrate that Nujol mulls can function as pseudo matrices over the temperature range 12–293 K, thereby considerably enhancing the usefulness and availability of low temperature studies of unstable species, especially for those derived from involatile precursors.
Published: 1987
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